A worker pushed a $22\mathrm{.}0$ kg block $11\mathrm{.}0$ m along a level floor at constant speed with a force directed $23\mathrm{.}0$ below the horizontal. If the coefficient of kinetic friction between block and floor was $0\mathrm{.}500,$ what were $($a$)$ the work done by the worker's force and $($b$)$ the increase in thermal energy of the block$-$floor system?

$($a$)$ Number

Units

$($b$)$ Number

Units